From 20b0059cdef058c2d4b8bce2cda3b2c2a86c1fe1 Mon Sep 17 00:00:00 2001
From: Frederik Deweerdt <frederik.deweerdt@gmail.com>
Date: Mon, 26 Sep 2022 17:51:03 -0700
Subject: [PATCH] Add stub functions for fastly purge

---
 lib/compute-at-edge-abi/compute-at-edge.witx |  9 +++++++++
 lib/compute-at-edge-abi/typenames.witx       | 16 ++++++++++++++++
 lib/src/linking.rs                           |  1 +
 lib/src/wiggle_abi.rs                        |  1 +
 lib/src/wiggle_abi/fastly_purge_impl.rs      | 19 +++++++++++++++++++
 5 files changed, 46 insertions(+)
 create mode 100644 lib/src/wiggle_abi/fastly_purge_impl.rs

diff --git a/lib/compute-at-edge-abi/compute-at-edge.witx b/lib/compute-at-edge-abi/compute-at-edge.witx
index a9884da2..2ae0eb37 100644
--- a/lib/compute-at-edge-abi/compute-at-edge.witx
+++ b/lib/compute-at-edge-abi/compute-at-edge.witx
@@ -486,3 +486,12 @@
         (result $err (expected (error $fastly_status)))
     )
 )
+
+(module $fastly_purge
+    (@interface func (export "purge_surrogate_key")
+        (param $surrogate_key string)
+        (param $options_mask $purge_options_mask)
+        (param $options (@witx pointer $purge_options))
+        (result $err (expected (error $fastly_status)))
+    )
+)
diff --git a/lib/compute-at-edge-abi/typenames.witx b/lib/compute-at-edge-abi/typenames.witx
index 850f0e84..530b80cb 100644
--- a/lib/compute-at-edge-abi/typenames.witx
+++ b/lib/compute-at-edge-abi/typenames.witx
@@ -162,3 +162,19 @@
     (field $sni_hostname (@witx pointer (@witx char8)))
     (field $sni_hostname_len u32)
     ))
+
+(typename $purge_options_mask
+    (flags (@witx repr u32)
+        $soft_purge
+        $ret_buf ;; all ret_buf fields must be populated
+    )
+)
+
+(typename $purge_options
+    (record
+        ;; JSON purge response as in https://developer.fastly.com/reference/api/purging/#purge-tag
+        (field $ret_buf_ptr (@witx pointer u8))
+        (field $ret_buf_len (@witx usize))
+        (field $ret_buf_nwritten_out (@witx pointer (@witx usize)))
+    )
+)
diff --git a/lib/src/linking.rs b/lib/src/linking.rs
index 58c48a07..be5bd278 100644
--- a/lib/src/linking.rs
+++ b/lib/src/linking.rs
@@ -88,6 +88,7 @@ pub fn link_host_functions(linker: &mut Linker<WasmCtx>) -> Result<(), Error> {
     wiggle_abi::fastly_http_resp::add_to_linker(linker, WasmCtx::session)?;
     wiggle_abi::fastly_log::add_to_linker(linker, WasmCtx::session)?;
     wiggle_abi::fastly_object_store::add_to_linker(linker, WasmCtx::session)?;
+    wiggle_abi::fastly_purge::add_to_linker(linker, WasmCtx::session)?;
     wiggle_abi::fastly_uap::add_to_linker(linker, WasmCtx::session)?;
     link_legacy_aliases(linker)?;
     Ok(())
diff --git a/lib/src/wiggle_abi.rs b/lib/src/wiggle_abi.rs
index 52f862c1..1d476b63 100644
--- a/lib/src/wiggle_abi.rs
+++ b/lib/src/wiggle_abi.rs
@@ -48,6 +48,7 @@ macro_rules! multi_value_result {
 mod body_impl;
 mod dictionary_impl;
 mod entity;
+mod fastly_purge_impl;
 mod geo_impl;
 mod headers;
 mod log_impl;
diff --git a/lib/src/wiggle_abi/fastly_purge_impl.rs b/lib/src/wiggle_abi/fastly_purge_impl.rs
new file mode 100644
index 00000000..59f704b3
--- /dev/null
+++ b/lib/src/wiggle_abi/fastly_purge_impl.rs
@@ -0,0 +1,19 @@
+//! fastly_purge` hostcall implementations.
+
+use {
+    super::types::{PurgeOptions, PurgeOptionsMask},
+    crate::{error::Error, session::Session, wiggle_abi::fastly_purge::FastlyPurge},
+    wiggle::GuestPtr,
+};
+
+impl FastlyPurge for Session {
+    #[allow(unused_variables)] // FIXME FDE 2022-09-26: Remove this directive once implemented.
+    fn purge_surrogate_key<'a>(
+        &mut self,
+        surrogate_key: &GuestPtr<'a, str>,
+        options_mask: PurgeOptionsMask,
+        options: &GuestPtr<'a, PurgeOptions<'a>>,
+    ) -> Result<(), Error> {
+        Err(Error::NotAvailable("FastlyPurge"))
+    }
+}